Sprinkle eggplant slices with kosher salt and let stand in a colander for 30 minutes. Combine olive oil, garlic, 4 T balsamic vinegar, chilies and salt and pepper. Lay Eggplant in a flat dish and cover with marinade. Let stand for 15 minutes. Grill eggplant slices over medium high heat (350-400) for approximately 2-3 minutes a side, or until you get good grill marks.